Air Microbiology: The presence of bacteria, viruses, and fungi in the air. This term is not restricted to pathogenic organisms.Aerosol Propellants: Compressed gases or vapors in a container which, upon release of pressure and expansion through a valve, carry another substance from the container. They are used for cosmetics, household cleaners, and so on. Examples are BUTANES; CARBON DIOXIDE; FLUOROCARBONS; NITROGEN; and PROPANE. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Nebulizers and Vaporizers: Devices that cause a liquid or solid to be converted into an aerosol (spray) or a vapor. It is used in drug administration by inhalation, humidification of ambient air, and in certain analytical instruments.Administration, Inhalation: The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.Particle Size: Relating to the size of solids.Acid Rain: Acidic water usually pH 2.5 to 4.5, which poisons the ecosystem and adversely affects plants, fishes, and mammals. It is caused by industrial pollutants, mainly sulfur oxides and nitrogen oxides, emitted into the atmosphere and returning to earth in the form of acidic rain water.Atmosphere: The gaseous envelope surrounding a planet or similar body. (From Random House Unabridged Dictionary, 2d ed)Inhalation Exposure: The exposure to potentially harmful chemical, physical, or biological agents by inhaling them.Humidity: A measure of the amount of WATER VAPOR in the air.Air Movements: The motion of air currents.Lung: Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.Sulfuric Acids: Inorganic and organic derivatives of sulfuric acid (H2SO4). The salts and esters of sulfuric acid are known as SULFATES and SULFURIC ACID ESTERS respectively.Powders: Substances made up of an aggregation of small particles, as that obtained by grinding or trituration of a solid drug. In pharmacy it is a form in which substances are administered. (From Dorland, 28th ed)Technetium Tc 99m Pentetate: A technetium imaging agent used in renal scintigraphy, computed tomography, lung ventilation imaging, gastrointestinal scintigraphy, and many other procedures which employ radionuclide imaging agents.Air Pollutants, Occupational: Air pollutants found in the work area. They are usually produced by the specific nature of the occupation.Smog: A mixture of smoke and fog polluting the atmosphere. (Dorland, 27th ed)Environmental Monitoring: The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.Air Pollutants: Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.Nasal Sprays: Pharmacologic agents delivered into the nostrils in the form of a mist or spray.Respiratory Protective Devices: Respirators to protect individuals from breathing air contaminated with harmful dusts, fogs, fumes, mists, gases, smokes, sprays, or vapors.Filtration: A process of separating particulate matter from a fluid, such as air or a liquid, by passing the fluid carrier through a medium that will not pass the particulates. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Beclomethasone: An anti-inflammatory, synthetic glucocorticoid. It is used topically as an anti-inflammatory agent and in aerosol form for the treatment of ASTHMA.Metered Dose Inhalers: A small aerosol canister used to release a calibrated amount of medication for inhalation.Albuterol: A short-acting beta-2 adrenergic agonist that is primarily used as a bronchodilator agent to treat ASTHMA. Albuterol is prepared as a racemic mixture of R(-) and S(+) stereoisomers. The stereospecific preparation of R(-) isomer of albuterol is referred to as levalbuterol.Meteorology: The science of studying the characteristics of the atmosphere such as its temperature, density, winds, clouds, precipitation, and other atmospheric phenomena and aiming to account for the weather in terms of external influences and the basic laws of physics. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Ventilation: Supplying a building or house, their rooms and corridors, with fresh air. The controlling of the environment thus may be in public or domestic sites and in medical or non-medical locales. (From Dorland, 28th ed)Particulate Matter: Particles of any solid substance, generally under 30 microns in size, often noted as PM30. There is special concern with PM1 which can get down to PULMONARY ALVEOLI and induce MACROPHAGE ACTIVATION and PHAGOCYTOSIS leading to FOREIGN BODY REACTION and LUNG DISEASES.Equipment Design: Methods of creating machines and devices.Dry Powder Inhalers: A device that delivers medication to the lungs in the form of a dry powder.Bronchodilator Agents: Agents that cause an increase in the expansion of a bronchus or bronchial tubes.Chlorofluorocarbons: A series of hydrocarbons containing both chlorine and fluorine. These have been used as refrigerants, blowing agents, cleaning fluids, solvents, and as fire extinguishing agents. They have been shown to cause stratospheric ozone depletion and have been banned for many uses.Respiratory System: The tubular and cavernous organs and structures, by means of which pulmonary ventilation and gas exchange between ambient air and the blood are brought about.Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Containment of Biohazards: Provision of physical and biological barriers to the dissemination of potentially hazardous biologically active agents (bacteria, viruses, recombinant DNA, etc.). Physical containment involves the use of special equipment, facilities, and procedures to prevent the escape of the agent. Biological containment includes use of immune personnel and the selection of agents and hosts that will minimize the risk should the agent escape the containment facility.Cromolyn Sodium: A chromone complex that acts by inhibiting the release of chemical mediators from sensitized mast cells. It is used in the prophylactic treatment of both allergic and exercise-induced asthma, but does not affect an established asthmatic attack.Atmosphere Exposure Chambers: Experimental devices used in inhalation studies in which a person or animal is either partially or completely immersed in a chemically controlled atmosphere.Dioctyl Sulfosuccinic Acid: All-purpose surfactant, wetting agent, and solubilizer used in the drug, cosmetics, and food industries. It has also been used in laxatives and as cerumenolytics. It is usually administered as either the calcium, potassium, or sodium salt.Dust: Earth or other matter in fine, dry particles. (Random House Unabridged Dictionary, 2d ed)Wind: The motion of air relative to the earth's surface.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.Cough: A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation. It is a protective response that serves to clear the trachea, bronchi, and/or lungs of irritants and secretions, or to prevent aspiration of foreign materials into the lungs.Respiratory Therapy: Care of patients with deficiencies and abnormalities associated with the cardiopulmonary system. It includes the therapeutic use of medical gases and their administrative apparatus, environmental control systems, humidification, aerosols, ventilatory support, bronchopulmonary drainage and exercise, respiratory rehabilitation, assistance with cardiopulmonary resuscitation, and maintenance of natural, artificial, and mechanical airways.Air Conditioning: The maintenance of certain aspects of the environment within a defined space to facilitate the function of that space; aspects controlled include air temperature and motion, radiant heat level, moisture, and concentration of pollutants such as dust, microorganisms, and gases. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Laboratory Infection: Accidentally acquired infection in laboratory workers.Air Pollution, Indoor: The contamination of indoor air.Threshold Limit Values: Standards for limiting worker exposure to airborne contaminants. They are the maximum concentration in air at which it is believed that a particular substance will not produce adverse health effects with repeated daily exposure. It can be a time-weighted average (TLV-TWA), a short-term value (TLV-STEL), or an instantaneous value (TLV-Ceiling). They are expressed either as parts per million (ppm) or milligram per cubic meter (mg/m3).Pentanes: Five-carbon saturated hydrocarbon group of the methane series. Include isomers and derivatives.Krypton: A noble gas that is found in the atmosphere. It has the atomic symbol Kr, atomic number 36, atomic weight 83.80, and has been used in electric bulbs.Biological Warfare Agents: Living organisms or their toxic products that are used to cause disease or death of humans during WARFARE.Copying Processes: Reproduction of data in a new location or other destination, leaving the source data unchanged, although the physical form of the result may differ from that of the source.Mucociliary Clearance: A non-specific host defense mechanism that removes MUCUS and other material from the LUNGS by ciliary and secretory activity of the tracheobronchial submucosal glands. It is measured in vivo as mucus transfer, ciliary beat frequency, and clearance of radioactive tracers.Masks: Devices that cover the nose and mouth to maintain aseptic conditions or to administer inhaled anesthetics or other gases. (UMDNS, 1999)Technetium: The first artificially produced element and a radioactive fission product of URANIUM. Technetium has the atomic symbol Tc, atomic number 43, and atomic weight 98.91. All technetium isotopes are radioactive. Technetium 99m (m=metastable) which is the decay product of Molybdenum 99, has a half-life of about 6 hours and is used diagnostically as a radioactive imaging agent. Technetium 99 which is a decay product of technetium 99m, has a half-life of 210,000 years.Fenoterol: An adrenergic beta-2 agonist that is used as a bronchodilator and tocolytic.Soot: A dark powdery deposit of unburned fuel residues, composed mainly of amorphous CARBON and some HYDROCARBONS, that accumulates in chimneys, automobile mufflers and other surfaces exposed to smoke. It is the product of incomplete combustion of carbon-rich organic fuels in low oxygen conditions. It is sometimes called lampblack or carbon black and is used in INK, in rubber tires, and to prepare CARBON NANOTUBES.Industrial Oils: Oils which are used in industrial or commercial applications.Chlorofluorocarbons, Methane: A group of methane-based halogenated hydrocarbons containing one or more fluorine and chlorine atoms.Bronchial Spasm: Spasmodic contraction of the smooth muscle of the bronchi.Bronchi: The larger air passages of the lungs arising from the terminal bifurcation of the TRACHEA. They include the largest two primary bronchi which branch out into secondary bronchi, and tertiary bronchi which extend into BRONCHIOLES and PULMONARY ALVEOLI.Ipratropium: A muscarinic antagonist structurally related to ATROPINE but often considered safer and more effective for inhalation use. It is used for various bronchial disorders, in rhinitis, and as an antiarrhythmic.Organic Chemicals: A broad class of substances containing carbon and its derivatives. Many of these chemicals will frequently contain hydrogen with or without oxygen, nitrogen, sulfur, phosphorus, and other elements. They exist in either carbon chain or carbon ring form.Gases: The vapor state of matter; nonelastic fluids in which the molecules are in free movement and their mean positions far apart. Gases tend to expand indefinitely, to diffuse and mix readily with other gases, to have definite relations of volume, temperature, and pressure, and to condense or liquefy at low temperatures or under sufficient pressure. (Grant & Hackh's Chemical Dictionary, 5th ed)Guinea Pigs: A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research.Drug Delivery Systems: Systems for the delivery of drugs to target sites of pharmacological actions. Technologies employed include those concerning drug preparation, route of administration, site targeting, metabolism, and toxicity.Airway Resistance: Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.ManikinsSpacecraft: Devices, manned and unmanned, which are designed to be placed into an orbit about the Earth or into a trajectory to another celestial body. (NASA Thesaurus, 1988)Ovalbumin: An albumin obtained from the white of eggs. It is a member of the serpin superfamily.Administration, Intranasal: Delivery of medications through the nasal mucosa.Physical Phenomena: The entities of matter and energy, and the processes, principles, properties, and relationships describing their nature and interactions.Pasteurella Infections: Infections with bacteria of the genus PASTEURELLA.Technology, Pharmaceutical: The application of scientific knowledge or technology to pharmacy and the pharmaceutical industry. It includes methods, techniques, and instrumentation in the manufacture, preparation, compounding, dispensing, packaging, and storing of drugs and other preparations used in diagnostic and determinative procedures, and in the treatment of patients.Metallurgy: The science, art, or technology dealing with processes involved in the separation of metals from their ores, the technique of making or compounding the alloys, the techniques of working or heat-treating metals, and the mining of metals. It includes industrial metallurgy as well as metallurgical techniques employed in the preparation and working of metals used in dentistry, with special reference to orthodontic and prosthodontic appliances. (From Jablonski, Dictionary of Dentistry, 1992, p494)Physics: The study of those aspects of energy and matter in terms of elementary principles and laws. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Air: The mixture of gases present in the earth's atmosphere consisting of oxygen, nitrogen, carbon dioxide, and small amounts of other gases.Atropine Derivatives: Analogs and derivatives of atropine.Coal: A natural fuel formed by partial decomposition of vegetable matter under certain environmental conditions.Bronchoalveolar Lavage Fluid: Washing liquid obtained from irrigation of the lung, including the BRONCHI and the PULMONARY ALVEOLI. It is generally used to assess biochemical, inflammatory, or infection status of the lung.Bronchial Provocation Tests: Tests involving inhalation of allergens (nebulized or in dust form), nebulized pharmacologically active solutions (e.g., histamine, methacholine), or control solutions, followed by assessment of respiratory function. These tests are used in the diagnosis of asthma.Sneezing: The sudden, forceful, involuntary expulsion of air from the NOSE and MOUTH caused by irritation to the MUCOUS MEMBRANES of the upper RESPIRATORY TRACT.Inhalation Spacers: A variety of devices used in conjunction with METERED DOSE INHALERS. Their purpose is to hold the released medication for inhalation and make it easy for the patients to inhale the metered dose of medication into their lungs.Snow: Frozen water crystals that fall from the ATMOSPHERE.Mycobacterium tuberculosis: A species of gram-positive, aerobic bacteria that produces TUBERCULOSIS in humans, other primates, CATTLE; DOGS; and some other animals which have contact with humans. Growth tends to be in serpentine, cordlike masses in which the bacilli show a parallel orientation.Ozone: The unstable triatomic form of oxygen, O3. It is a powerful oxidant that is produced for various chemical and industrial uses. Its production is also catalyzed in the ATMOSPHERE by ULTRAVIOLET RAY irradiation of oxygen or other ozone precursors such as VOLATILE ORGANIC COMPOUNDS and NITROGEN OXIDES. About 90% of the ozone in the atmosphere exists in the stratosphere (STRATOSPHERIC OZONE).National Institute for Occupational Safety and Health (U.S.): An institute of the CENTERS FOR DISEASE CONTROL AND PREVENTION which is responsible for assuring safe and healthful working conditions and for developing standards of safety and health. Research activities are carried out pertinent to these goals.Trachea: The cartilaginous and membranous tube descending from the larynx and branching into the right and left main bronchi.Hydrocarbons, FluorinatedOxocins: Compounds based on an 8-membered heterocyclic ring including an oxygen. They can be considered medium ring ethers.Respiratory Function Tests: Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.Freeze Drying: Method of tissue preparation in which the tissue specimen is frozen and then dehydrated at low temperature in a high vacuum. This method is also used for dehydrating pharmaceutical and food products.Bronchial Hyperreactivity: Tendency of the smooth muscle of the tracheobronchial tree to contract more intensely in response to a given stimulus than it does in the response seen in normal individuals. This condition is present in virtually all symptomatic patients with asthma. The most prominent manifestation of this smooth muscle contraction is a decrease in airway caliber that can be readily measured in the pulmonary function laboratory.Disease Models, Animal: Naturally occurring or experimentally induced animal diseases with pathological processes sufficiently similar to those of human diseases. They are used as study models for human diseases.Metaproterenol: A beta-2 adrenergic agonist used in the treatment of ASTHMA and BRONCHIAL SPASM.Nose: A part of the upper respiratory tract. It contains the organ of SMELL. The term includes the external nose, the nasal cavity, and the PARANASAL SINUSES.Chemistry, Organic: The study of the structure, preparation, properties, and reactions of carbon compounds. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Models, Anatomic: Three-dimensional representation to show anatomic structures. Models may be used in place of intact animals or organisms for teaching, practice, and study.Budesonide: A glucocorticoid used in the management of ASTHMA, the treatment of various skin disorders, and allergic RHINITIS.Bronchoconstriction: Narrowing of the caliber of the BRONCHI, physiologically or as a result of pharmacological intervention.Forensic Ballistics: The science of studying projectiles in motion, ballistics, being applied to law. Ballistics on firearm projectiles, such as bullets, include the study of what happens inside the weapon, during the flight of the projectile, and when the projectile strikes the target, such as body tissue.Sulfur Dioxide: A highly toxic, colorless, nonflammable gas. It is used as a pharmaceutical aid and antioxidant. It is also an environmental air pollutant.Nitric Acid: Nitric acid (HNO3). A colorless liquid that is used in the manufacture of inorganic and organic nitrates and nitro compounds for fertilizers, dye intermediates, explosives, and many different organic chemicals. Continued exposure to vapor may cause chronic bronchitis; chemical pneumonitis may occur. (From Merck Index, 11th ed)Respiratory Mechanics: The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Nanoparticles: Nanometer-sized particles that are nanoscale in three dimensions. They include nanocrystaline materials; NANOCAPSULES; METAL NANOPARTICLES; DENDRIMERS, and QUANTUM DOTS. The uses of nanoparticles include DRUG DELIVERY SYSTEMS and cancer targeting and imaging.Burkholderia mallei: A species of gram-negative bacteria parasitic on HORSES and DONKEYS causing GLANDERS, which can be transmitted to humans.Terbutaline: A selective beta-2 adrenergic agonist used as a bronchodilator and tocolytic.Anthrax: An acute infection caused by the spore-forming bacteria BACILLUS ANTHRACIS. It commonly affects hoofed animals such as sheep and goats. Infection in humans often involves the skin (cutaneous anthrax), the lungs (inhalation anthrax), or the gastrointestinal tract. Anthrax is not contagious and can be treated with antibiotics.Tuberculosis Vaccines: Vaccines or candidate vaccines used to prevent or treat TUBERCULOSIS.Forced Expiratory Volume: Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.Histamine: An amine derived by enzymatic decarboxylation of HISTIDINE. It is a powerful stimulant of gastric secretion, a constrictor of bronchial smooth muscle, a vasodilator, and also a centrally acting neurotransmitter.Technetium Tc 99m Aggregated Albumin: A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in cardiovascular and cerebral circulation.Respiratory System Agents: Drugs used for their effects on the respiratory system.Plutonium: Plutonium. A naturally radioactive element of the actinide metals series. It has the atomic symbol Pu, atomic number 94, and atomic weight 242. Plutonium is used as a nuclear fuel, to produce radioisotopes for research, in radionuclide batteries for pacemakers, and as the agent of fission in nuclear weapons.Polyethyleneimine: Strongly cationic polymer that binds to certain proteins; used as a marker in immunology, to precipitate and purify enzymes and lipids. Synonyms: aziridine polymer; Epamine; Epomine; ethylenimine polymer; Montrek; PEI; Polymin(e).Respiratory Transport: The processes of diffusion across the BLOOD-AIR BARRIER, and the chemical reactions coupled with diffusion that effect the rate of PULMONARY GAS EXCHANGE, generally at the alveolar level.Power Plants: Units that convert some other form of energy into electrical energy.Solar System: The group of celestial bodies, including the EARTH, orbiting around and gravitationally bound by the sun. It includes eight planets, one minor planet, and 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as MINOR PLANETS (asteroids) and METEOROIDS. (From Academic American Encyclopedia, 1983)Methacholine Chloride: A quaternary ammonium parasympathomimetic agent with the muscarinic actions of ACETYLCHOLINE. It is hydrolyzed by ACETYLCHOLINESTERASE at a considerably slower rate than ACETYLCHOLINE and is more resistant to hydrolysis by nonspecific CHOLINESTERASES so that its actions are more prolonged. It is used as a parasympathomimetic bronchoconstrictor agent and as a diagnostic aid for bronchial asthma. (From Martindale, The Extra Pharmacopoeia, 30th ed, p1116)Harmful Algal Bloom: An algal bloom where the algae produce powerful toxins that can kill fish, birds, and mammals, and ultimately cause illness in humans. The harmful bloom can also cause oxygen depletion in the water due to the death and decomposition of non-toxic algae species.Chemistry, Pharmaceutical: Chemistry dealing with the composition and preparation of agents having PHARMACOLOGIC ACTIONS or diagnostic use.Respiration: The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).Maximal Expiratory Flow Rate: The airflow rate measured during the first liter expired after the first 200 ml have been exhausted during a FORCED VITAL CAPACITY determination. Common abbreviations are MEFR, FEF 200-1200, and FEF 0.2-1.2.Piperaceae: A family of flowering plants in the order Piperales best known for the black pepper widely used in SPICES, and for KAVA and Betel used for neuroactive properties.Lung Diseases: Pathological processes involving any part of the LUNG.Mice, Inbred BALB CAircraft: A weight-carrying structure for navigation of the air that is supported either by its own buoyancy or by the dynamic action of the air against its surfaces. (Webster, 1973)Tuberculosis, Pulmonary: MYCOBACTERIUM infections of the lung.Dental Offices: The room or rooms in which the dentist and dental staff provide care. Offices include all rooms in the dentist's office suite.Francisella tularensis: The etiologic agent of TULAREMIA in man and other warm-blooded animals.Convection: Transmission of energy or mass by a medium involving movement of the medium itself. The circulatory movement that occurs in a fluid at a nonuniform temperature owing to the variation of its density and the action of gravity. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed; Webster, 10th ed)Orthomyxoviridae Infections: Virus diseases caused by the ORTHOMYXOVIRIDAE.Hemiterpenes: The five-carbon building blocks of TERPENES that derive from MEVALONIC ACID or deoxyxylulose phosphate.Alveolitis, Extrinsic Allergic: A common interstitial lung disease caused by hypersensitivity reactions of PULMONARY ALVEOLI after inhalation of and sensitization to environmental antigens of microbial, animal, or chemical sources. The disease is characterized by lymphocytic alveolitis and granulomatous pneumonitis.Pulmonary Ventilation: The total volume of gas inspired or expired per unit of time, usually measured in liters per minute.Respiratory Hypersensitivity: A form of hypersensitivity affecting the respiratory tract. It includes ASTHMA and RHINITIS, ALLERGIC, SEASONAL.Airway Obstruction: Any hindrance to the passage of air into and out of the lungs.Ribonucleosides: Nucleosides in which the purine or pyrimidine base is combined with ribose. (Dorland, 28th ed)Models, Theoretical: Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.Hydrodynamics: The motion of fluids, especially noncompressible liquids, under the influence of internal and external forces.Sulfates: Inorganic salts of sulfuric acid.Colony Count, Microbial: Enumeration by direct count of viable, isolated bacterial, archaeal, or fungal CELLS or SPORES capable of growth on solid CULTURE MEDIA. The method is used routinely by environmental microbiologists for quantifying organisms in AIR; FOOD; and WATER; by clinicians for measuring patients' microbial load; and in antimicrobial drug testing.Respiratory Tract DiseasesBronchoconstrictor Agents: Agents causing the narrowing of the lumen of a bronchus or bronchiole.Saturn: The sixth planet in order from the sun. It is one of the five outer planets of the solar system. Its twelve natural satellites include Phoebe and Titan.Pentetic Acid: An iron chelating agent with properties like EDETIC ACID. DTPA has also been used as a chelator for other metals, such as plutonium.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.Ventilation-Perfusion Ratio: The ratio of alveolar ventilation to simultaneous alveolar capillary blood flow in any part of the lung. (Stedman, 25th ed)Peptones: Derived proteins or mixtures of cleavage products produced by the partial hydrolysis of a native protein either by an acid or by an enzyme. Peptones are readily soluble in water, and are not precipitable by heat, by alkalis, or by saturation with ammonium sulfate. (Dorland, 28th ed)Isocyanates: Organic compounds that contain the -NCO radical.Air Pressure: The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.Paranasal Sinuses: Air-filled spaces located within the bones around the NASAL CAVITY. They are extensions of the nasal cavity and lined by the ciliated NASAL MUCOSA. Each sinus is named for the cranial bone in which it is located, such as the ETHMOID SINUS; the FRONTAL SINUS; the MAXILLARY SINUS; and the SPHENOID SINUS.Vital Capacity: The volume of air that is exhaled by a maximal expiration following a maximal inspiration.Cystic Fibrosis: An autosomal recessive genetic disease of the EXOCRINE GLANDS. It is caused by mutations in the gene encoding the CYSTIC FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR expressed in several organs including the LUNG, the PANCREAS, the BILIARY SYSTEM, and the SWEAT GLANDS. Cystic fibrosis is characterized by epithelial secretory dysfunction associated with ductal obstruction resulting in AIRWAY OBSTRUCTION; chronic RESPIRATORY INFECTIONS; PANCREATIC INSUFFICIENCY; maldigestion; salt depletion; and HEAT PROSTRATION.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Pulmonary Alveoli: Small polyhedral outpouchings along the walls of the alveolar sacs, alveolar ducts and terminal bronchioles through the walls of which gas exchange between alveolar air and pulmonary capillary blood takes place.WeldingNedocromil: A pyranoquinolone derivative that inhibits activation of inflammatory cells which are associated with ASTHMA, including eosinophils, neutrophils, macrophages, mast cells, monocytes, and platelets.Marine Toxins: Toxic or poisonous substances elaborated by marine flora or fauna. They include also specific, characterized poisons or toxins for which there is no more specific heading, like those from poisonous FISHES.Volcanic Eruptions: The ash, dust, gases, and lava released by volcanic explosion. The gases are volatile matter composed principally of about 90% water vapor, and carbon dioxide, sulfur dioxide, hydrogen, carbon monoxide, and nitrogen. The ash or dust is pyroclastic ejecta and lava is molten extrusive material consisting mainly of magnesium silicate. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Serratia marcescens: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in soil, water, food, and clinical specimens. It is a prominent opportunistic pathogen for hospitalized patients.Mucus: The viscous secretion of mucous membranes. It contains mucin, white blood cells, water, inorganic salts, and exfoliated cells.Xenon Radioisotopes: Unstable isotopes of xenon that decay or disintegrate emitting radiation. Xe atoms with atomic weights 121-123, 125, 127, 133, 135, 137-145 are radioactive xenon isotopes.Climate: The longterm manifestations of WEATHER. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)PaintAllergens: Antigen-type substances that produce immediate hypersensitivity (HYPERSENSITIVITY, IMMEDIATE).Glanders: A contagious disease of horses that can be transmitted to humans. It is caused by BURKHOLDERIA MALLEI and characterized by ulceration of the respiratory mucosa and an eruption of nodules on the skin.Pregnenediones: Unsaturated pregnane derivatives containing two keto groups on side chains or ring structures.Saline Solution, Hypertonic: Hypertonic sodium chloride solution. A solution having an osmotic pressure greater than that of physiologic salt solution (0.9 g NaCl in 100 ml purified water).Tularemia: A plague-like disease of rodents, transmissible to man. It is caused by FRANCISELLA TULARENSIS and is characterized by fever, chills, headache, backache, and weakness.Suspensions: Colloids with liquid continuous phase and solid dispersed phase; the term is used loosely also for solid-in-gas (AEROSOLS) and other colloidal systems; water-insoluble drugs may be given as suspensions.Environment, Controlled: A state in which the environs of hospitals, laboratories, domestic and animal housing, work places, spacecraft, and other surroundings are under technological control with regard to air conditioning, heating, lighting, humidity, ventilation, and other ambient features. The concept includes control of atmospheric composition. (From Jane's Aerospace Dictionary, 3d ed)Chrysanthemum cinerariifolium: A plant species of the genus CHRYSANTHEMUM, family ASTERACEAE. The flowers contain PYRETHRINS, cinerolones, and chrysanthemines which are powerful contact insecticides. Most in the old Pyrethrum genus are reclassified to TANACETUM; some to other ASTERACEAE genera.Lung Compliance: The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)Respiratory Tract Infections: Invasion of the host RESPIRATORY SYSTEM by microorganisms, usually leading to pathological processes or diseases.Equipment and Supplies: Expendable and nonexpendable equipment, supplies, apparatus, and instruments that are used in diagnostic, surgical, therapeutic, scientific, and experimental procedures.Plague: An acute infectious disease caused by YERSINIA PESTIS that affects humans, wild rodents, and their ectoparasites. This condition persists due to its firm entrenchment in sylvatic rodent-flea ecosystems throughout the world. Bubonic plague is the most common form.Exhalation: The act of BREATHING out.Antitussive Agents: Agents that suppress cough. They act centrally on the medullary cough center. EXPECTORANTS, also used in the treatment of cough, act locally.Inhalation: The act of BREATHING in.Volatilization: A phase transition from liquid state to gas state, which is affected by Raoult's law. It can be accomplished by fractional distillation.BCG Vaccine: An active immunizing agent and a viable avirulent attenuated strain of Mycobacterium tuberculosis, var. bovis, which confers immunity to mycobacterial infections. It is used also in immunotherapy of neoplasms due to its stimulation of antibodies and non-specific immunity.Lethal Dose 50: The dose amount of poisonous or toxic substance or dose of ionizing radiation required to kill 50% of the tested population.Encephalomyelitis, Venezuelan Equine: A form of arboviral encephalitis endemic to Central America and the northern latitudes of South America. The causative organism (ENCEPHALITIS VIRUS, VENEZUELAN EQUINE) is transmitted to humans and horses via the bite of several mosquito species. Human viral infection may be asymptomatic or remain restricted to a mild influenza-like illness. Encephalitis, usually not severe, occurs in a small percentage of cases and may rarely feature SEIZURES and COMA. (From Joynt, Clinical Neurology, 1996, Ch26, pp9-10)Nasal Cavity: The proximal portion of the respiratory passages on either side of the NASAL SEPTUM. Nasal cavities, extending from the nares to the NASOPHARYNX, are lined with ciliated NASAL MUCOSA.Actinobacillus pleuropneumoniae: A species of gram-negative, facultatively anaerobic coccobacillus-shaped bacteria that has been isolated from pneumonic lesions and blood. It produces pneumonia with accompanying fibrinous pleuritis in swine.Pneumonia: Infection of the lung often accompanied by inflammation.Helium: Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)Legionella: Gram-negative aerobic rods, isolated from surface water or thermally polluted lakes or streams. Member are pathogenic for man. Legionella pneumophila is the causative agent for LEGIONNAIRES' DISEASE.Sodium Chloride: A ubiquitous sodium salt that is commonly used to season food.HydrocarbonsToxicity Tests: An array of tests used to determine the toxicity of a substance to living systems. These include tests on clinical drugs, foods, and environmental pollutants.Encephalitis Virus, Venezuelan Equine: A species of ALPHAVIRUS that is the etiologic agent of encephalomyelitis in humans and equines. It is seen most commonly in parts of Central and South America.Pentamidine: Antiprotozoal agent effective in trypanosomiasis, leishmaniasis, and some fungal infections; used in treatment of PNEUMOCYSTIS pneumonia in HIV-infected patients. It may cause diabetes mellitus, central nervous system damage, and other toxic effects.Optical Processes: Behavior of LIGHT and its interactions with itself and materials.Bacteriological Techniques: Techniques used in studying bacteria.Volatile Organic Compounds: Organic compounds that have a relatively high VAPOR PRESSURE at room temperature.Encephalomyelitis, Equine: A group of ALPHAVIRUS INFECTIONS which affect horses and man, transmitted via the bites of mosquitoes. Disorders in this category are endemic to regions of South America and North America. In humans, clinical manifestations vary with the type of infection, and range from a mild influenza-like syndrome to a fulminant encephalitis. (From Joynt, Clinical Neurology, 1996, Ch26, pp8-10)Satellite Communications: Communications using an active or passive satellite to extend the range of radio, television, or other electronic transmission by returning signals to earth from an orbiting satellite.Citric Acid: A key intermediate in metabolism. It is an acid compound found in citrus fruits. The salts of citric acid (citrates) can be used as anticoagulants due to their calcium chelating ability.Technetium Tc 99m Sulfur Colloid: A gamma-emitting radionuclide imaging agent used for the diagnosis of diseases in many tissues, particularly in the gastrointestinal system, liver, and spleen.Clinical Trials as Topic: Works about pre-planned studies of the safety, efficacy, or optimum dosage schedule (if appropriate) of one or more diagnostic, therapeutic, or prophylactic drugs, devices, or techniques selected according to predetermined criteria of eligibility and observed for predefined evidence of favorable and unfavorable effects. This concept includes clinical trials conducted both in the U.S. and in other countries.